Performance of a sense amplifier depends on manufacturing processes to manufacture transistors in the amplifier. For example, two transistors manufactured by a same process are supposed to have the same characteristics and/or behave in a same manner. Because of manufacturing process variations, however, characteristics and behaviors of the two transistors are not the same. Explained in a different way, a mismatch between the two transistors exists.
For illustration, the sense amplifier is used to sense a voltage difference on two data lines of a memory cell. The voltage difference is also called a data split. In a read operation of the memory cell, initially, the data split is smaller than a sensing threshold of the sense amplifier. As a result, the sense amplifier cannot sense the data, but has to wait for the data split to develop and becomes larger than the sensing threshold. Because of mismatches of transistors in the sense amplifier, the wait time increases. Consequently, a sensing speed of the sense amplifier decreases.
Like reference symbols in the various drawings indicate like elements.